That could easily change though. If you start having content with two mobs to burn, swashies get their HP debuff back.
If the benefit they are bringing dps wise is far better for the raid, even with a small drop in their own dos, they are on top.
Anything where a tank wants extra hate transfer (perhaps not apt if you have good tanks, but not ever raid does) swashies win again.
Offensive debuff a needed? 2x swipe needed? Swashies again.
I'd like to see some reason for assassins not to be guaranteed a raid spot though sadly. HP debuffs are basically the only reason.